Twin pregnancy experimental model for transvaginal ultrasound-guided twin reduction in mares

Multiple pregnancies are still an important cause of noninfectious abortion, stillbirth, neonatal mortality, and significant delays in reproductive performance in mares. Despite new management techniques, reduction in multiple pregnancies is an ongoing preoccupation and challenge for the equine veterinarian. The aim of the present study was to establish a twin pregnancy experimental model in the mare to study the effectiveness of a transvaginal ultrasound-guided embryonic vesicle injection. Mares in heat were inseminated and then received an embryo at day 7 of the estrous cycle. At days 14 and 30, 53.5% (n = 23) and 23% (n = 10) of the mares, respectively, were carrying twins. Twin pregnancies were reduced at day 30 by transvaginal ultrasound-guided puncture of the embryonic vesicle (control, n = 5) or by transvaginal ultrasound-guided injection (TVUEVI) of 25 mg of amikacin into the embryonic vesicle (n = 5). The TVUEVI treatment had a 40% success rate and no significant variations in progesterone and prostaglandin metabolite were observed. Even though the technique does not seem very effective, the experimental model could be useful for clinical research in embryo reduction and early embryonic loss.     

Cytochrome P450 3A, NADPH cytochrome P450 reductase and cytochrome b5 in the upper airways in horse

Gene and protein expression as well as catalytic activity of cytochrome P450 (CYP) 3A were studied in the nasal olfactory and respiratory mucosa and the tracheal mucosa of the horse. We also examined the activity of NADPH cytochrome P450 reductase (NADPH P450 reductase), the amount of cytochrome b(5) and the total CYP content in these tissues. Comparative values for the above were obtained using liver as a control. The CYP3A related catalytic activity in the tissues of the upper airways was considerably higher than in the liver. The CYP3A gene and protein expression, on the other hand, was higher in the liver than in the upper airway tissues. Thus, the pattern of CYP3A metabolic activity does not correlate with the CYP3A gene and protein expression. Our results showed that the activity of NADPH P450 reductase and the level of cytochrome b(5) in the relation to the gene and protein expression of CYP3A were higher in the tissues of the upper airways than in the liver. It is concluded that CYP3A related metabolism in horse is not solely dependent on the expression of the enzyme but also on adequate levels of NADPH P450 reductase and cytochrome b(5).     

A multicentric retrospective study of serum/plasma urea and creatinine concentrations in dogs using univariate and multivariate decision rules to evaluate diagnostic efficiency

BACKGROUND: Urea and creatinine are the most frequently used indirect markers in plasma and serum of glomerular filtration rate in dogs. Both have been shown to lack sensitivity but their diagnostic efficiency for the diagnosis of kidney disease has been minimally investigated. OBJECTIVE: The purpose of this retrospective study was to investigate the influence of possible factors of variation on both analytes and to determine whether specific decision rules should be drawn up for subpopulations of dogs. METHODS: The results of urea and creatinine measurements, breed, sex, age, and health status (healthy, renal disease, or nonrenal disease) of 3822 dogs were collected from the archives of 5 veterinary clinics. Data were analyzed with univariate and multivariate decision rules with and without adjustment. RESULTS: There were significant effects and interactions of almost all of the sources of variation. Slight improvements in diagnostic efficiency were obtained by adjusting the decision rules to these sources of variations. Univariate decision rules gave approximately the same diagnostic efficiency for urea and creatinine concentrations, with sensitivity and specificity in the range of 70% and 90%, respectively, using the upper limit of the reference interval as the threshold value. Multivariate decision rules provided only minor improvements in diagnostic efficiency. CONCLUSION: Simultaneous measurement of both urea and creatinine is of limited diagnostic value over the analysis of a single variable. Creatinine is the preferred analyte as it is affected by fewer extrarenal factors of variation.     

Artifacts in digital radiography

Digital radiography is becoming more prevalent in veterinary medicine, and with its increased use has come the recognition of a number of artifacts. Artifacts in digital radiography can decrease image quality and mask or mimic pathologic changes. They can be categorized according to the step during which they are created and include preexposure, exposure, postexposure, reading, and workstation artifacts. The recognition and understanding of artifacts in digital radiography facilitates their reduction and decreases misinterpretation. The purpose of this review is to name, describe the appearance, identify the cause, and provide methods of resolution of artifacts in digital radiography.     

The Diurnal Variation of Urea in Cow’s Milk and how Milk Fat Content,Storage and Preservation Affects Analysis by a Flow Injection Technique

Six Swedish Red and White dairy cows, producing 20-39 kg of 4% fat-corrected milk were given a ration balanced in energy and protein. They had access to feed from 05.15 to 09.00 and from 13.00 to 16.30 and were milked at 06.15 and 15.30. The milk was analysed for urea with a FIA technique.There was a significant diurnal variation in milk urea. The highest values were found 3–5 h after the beginning of the morning feeding and the lowest values (down to 60% of the max. values) during late night. Within 1 h after the start of the morning feeding the urea values had increased significantly, but they had decreased within the same time after the start of the afternoon feeding. Since there was a pronounced diurnal variation in the milk fat content, the urea concentration was also recalculated to concentration in the water phase of the milk. It was higher in that phase, but the pattern of the diurnal variation was not changed significantly. However, analyses on milk with a very high fat content may give misleading results.There were no important differences in the milk urea concentration of different udder quarters. When calculated as concentration in the water phase of the milk, no differences in urea concentration were found between the beginning and the end of milking. The analytical method had a good precision (coefficient of variation max. 3%). The milk urea concentration was not changed significantly after storage during 10 days at 4°C when no preservative was added; but after 17 days the milk had turned sour and the urea value had increased. When a preservative (bronopole) was added the urea concentration remained unchanged during 17 days. Deepfreezing did not influence the urea concentration.     

Changes in the plasma concentrations of prolactin,luteinising hormone,progesterone and d‐(β)‐hydroxybutyrate in turkey hens (meleagris gallopavo), during treatment of broodiness under commercial conditions

1. An experiment was done under commercial conditions to investigate the physiological effects of isolating broody turkey hens, for 72 h, in sand and wire floored pens on the third, 10th and 16th weeks of production.

2. Hens identified as broody and removed from the flock had higher plasma prolactin concentrations than the laying hens at each of the three experimental stages.

3. Confinement in sand and wire floored pens, induced a decline in plasma prolactin concentrations. This decline probably impeded immediate development of broody behaviour. Alternately, levels of prolactin higher than those of laying hens were again measured 7 and 14 days after treatment during third week but not after the 10 th and 16th week of production.

4. Confinement did not induce consistent changes in luteinising hormone (LH) and progesterone concentrations from one period to an other.

5. An increase in the plasma concentration of D‐(/?)‐hydroxybutyrate was observed in the hens which had an egg present in the oviduct on day 2, 3 and/or 4 of the treatment. Subsequently, a decrease in ovulation rate was observed in the hens with higher concentrations of D‐(β)‐hydroxybutyrate while under treatment, during the 10th week of production.

6. These data confirm that the effectiveness of the traditional methods for broodiness prevention under commercial conditions is related to the induction of a decrease of prolactin.     

Identification of carcass and meat quality quantitative trait loci in a Landrace pig population selected for growth and leanness

The identification of QTL related to production traits that are relevant for the pig industry has been mostly performed by using divergent crosses. The main objective of the current study was to investigate whether these growth, fatness, and meat quality QTL, previously described in diverse experimental populations, were segregating in a Landrace commercial population selected for litter size, backfat thickness, and growth performance. We have found QTL for carcass weight (posterior P > 0.75), cutlet weight (posterior P > 0.99), weight of ham (posterior P > 0.75), shoulders weight (posterior probability > 0.99), and shear firm-ness (posterior P > 0.99) on pig Chromosome 2. Moreover, QTL with posterior P > 0.75 for fat thickness between the 3rd and 4th ribs (Chromosome 7), rib weights (Chromosome 8), backfat thickness (Chromosomes 8, 9, and 10), and b Minolta color component (Chromosome 7) were identified. These results indicate that commercial purebred populations retain a significant amount of genetic variation, even for traits that have been selected for many generations.     

A novel epidemiological model to better understand and predict the observed seasonal spread of Pestivirus in Pyrenean chamois populations

Seasonal variations in individual contacts give rise to a complex interplay between host demography and pathogen transmission. This is particularly true for wild populations, which highly depend on their natural habitat. These seasonal cycles induce variations in pathogen transmission. The seasonality of these biological processes should therefore be considered to better represent and predict pathogen spread. In this study, we sought to better understand how the seasonality of both the demography and social contacts of a mountain ungulate population impacts the spread of a pestivirus within, and the dynamics of, this population. We propose a mathematical model to represent this complex biological system. The pestivirus can be transmitted both horizontally through direct contact and vertically in utero. Vertical transmission leads to abortion or to the birth of persistently infected animals with a short life expectancy. Horizontal transmission involves a complex dynamics because of seasonal variations in contact among sexes and age classes. We performed a sensitivity analysis that identified transmission rates and disease-related mortality as key parameters. We then used data from a long-term demographic and epidemiological survey of the studied population to estimate these mostly unknown epidemiological parameters. Our model adequately represents the system dynamics, observations and model predictions showing similar seasonal patterns. We show that the virus has a significant impact on population dynamics, and that persistently infected animals play a major role in the epidemic dynamics. Modeling the seasonal dynamics allowed us to obtain realistic prediction and to identify key parameters of transmission.

Electronic supplementary material

The online version of this article (doi:10.1186/s13567-015-0218-8) contains supplementary material, which is available to authorized users.     

Early detection of bovine respiratory disease in young bulls using reticulo-rumen temperature boluses

The use of reticulo-rumen temperature boluses to detect bovine respiratory disease (BRD) was investigated in young bulls following their entry into a fattening unit. Twenty-four bulls received a bolus at entry and were observed for 40 days. As soon as a reticulo-rumen hyperthermia (RH) episode was detected using the bolus, clinical examination was performed by a veterinarian and then repeated every 12-24h until the end of RH episode. Fifty-two RH episodes were detected in 22 animals. High rectal temperatures (40.1±0.6°C) were observed during these episodes. BRD was diagnosed on the basis of clinical examination during 38/52 RH episodes in 21 animals (positive predictive value 73%). The onset of BRD signs always occurred after the onset of RH episodes, with a time-lag from 12 to 136 h, depending on BRD signs. Monitoring reticulo-rumen temperature permits early detection of BRD; however, clinical examination is required to confirm BRD.